Placement of Controllers in Software Defined Networking under Multiple Controller Mapping

This work focuses on the placement of controllers in software-defined networking architectures. A mathematical model is developed to place controllers under multi- controller switch-controller mapping, where a switch can be assigned to multiple controllers. Resiliency, scalability, and inter-plane latency are all modeled in the proposed model. A scalability factor is introduced to increase the load to capacity gap at controllers, preventing controllers to work near their capacity limit. The proposed model is shown to be effective and resilient under different failure scenarios while, at the same time, taking latency and scalability into consideration. Keywords: Controller Placement, Software-defined Networking, Reliability, Scalability

A PSO-Based Recurrent Closed-Loop Optimization Method for Multiple Controller Single-Output Thermal Engineering Systems

For solving the problems of closed-loop optimization on controller parameters of multiple-controller single-output thermal engineering system, this paper proposes a recurrent optimization method that is based on the particle swarm computing and closed-loop simulation (PSO-RCO). It consists of a set of closed-loop identification, simulation, and optimization functions that are organized in a recurrent working flow. The working flow makes one controller tuned at a time whilst others keep their values. It ends after several rounds of overall optimizations. Such a recurrently alternative tuning can greatly speed up the convergence of controller parameters to reasonable values. Verifications on practical data from a superheated steam temperature control system show that the optimized control system performance is greatly improved by reasonable controller parameters and practicable control action. With the advantage of not interfering system operation and the potential supporting on big data identification method, the PSO-RCO is a promising method for control system optimization.

A New Algorithm for Controller Placement in SDN

SDN network supports centralized network management by splitting control plane and data plane of forwarding devices and places the network intelligence in a software entity called controller. The controller can be placed in selective places of network to effectively monitor and control network activities. Large scale network needs multiple controller to manage control activities of network. In order to identify the optimum number of controllers and its effective locations in the network, a new algorithm is proposed using cut-vertex concept from graph theory. The proposed algorithm is simulated using Mininet SDN emulator. To study the performance of the proposed algorithm, multiple scenarios were used in the simulation and performance was analysed using parameters viz., flow installation time, average latency of network, throughput.